Elevator for flowable material



March 15, 1966 s. H. BACKSTROM ELEVATOR FOR FLOWABLE MATERIAL 2 Sheets-Sheet 1 Filed Jan. 24, 1964 NF mm NM 3 S March 15, 1966 s. H. BACKSTRGM 3,240,367

ELEVATOR FOR FLOWABLE MATERIAL Filed Jan. 24, 1964 2 Sheets-Sheet 2 Il /II/I/II/IIII/II/ t Mn W M United States Patent 3,240,367 ELEVATOR FOR FLOWABLE MATERIAL Sven Hjalmar Backsn'iim, Tunabro, Sweden, assignor to Stora Kopparbergs Bergslags Aktiebolag, Falun, Sweden, a company of Sweden Filed Jan. 24, 1964, Ser. No. 340,021 Claims priority, application Sweden, Feb. 1, 1963, 1,141/ 63 17 Claims. (Cl. 214-18) The invention relates to the transport of material and particularly the elevation of flowable material, such as powder or granular material, from one level to another, and it has for its object an elevator for lifting flowable material, especially particle material, such as disintegrated and possibly metallurgically treated ore or ore concentrate from a charging position to a discharging position at a higher level, particularly for the feeding of material from the bottom portion of one of two coaxial rotary drums to the top portion of the other. As a practical case of application there may be referred to a rotary furnace for treating ore material and a tubular heat exchanger coaxially secured thereto, in which the material introduced into the tubes shall be preheated by mate-rial treated in and returned from the treating furnace. It has appeared to be difficult to transfer the material from the bottom of the treating furnace to a high level in the tubular heat exchanger which is, however, desirable because from economical point of view it is a desideratum to obtain a high degree of filling, i.e. to obtain reduction in the length of the heat exchanger and of torque.

It is an object of the invention to eliminate said disadvantage, i.e. in a simple and cheap manner to lift material of said nature to a level which is high relative to the lifting members.

For obtaining the object of the invention and other advantages not mentioned, the elevator according to the invention is characterized in a container rotatable in a substantially vertical circular path between said positions, the container having inlets and outlets for the material in its fore part, in the direction of rotation, and a partition wall between said inlet and outlet for the formation of separate charging and discharging compartments and a pocket in the rear part of the container communicating with said compartments. The peripheral limitation wall of the container is preferably cylindrical. The elevator can be said to consist of a ring where the container is a segment, the ring preferably comprising a plurality of containers arranged one after the other, whereby the efliciency is increased, in particular if separate feeding members are arranged for each container.

Since in the application of the invention it is usually the question of feeding material from the bottom of a furnace or another chamber to the upper portion of a chamber connected thereto the feed will take place from the one side of the elevator to the other. It is then appropriate that the charging and discharging compartments are positioned at substantially the same radial level. They will then be located side by side and the inlet and outlet openings to the compartments may be arranged in the vertical limitation walls of the container. It is often advantageous that the charging opening be arranged in the substantially radially positioned fore limitation wall of the charging compartments, preferably near the vertical outer limitation wall of the compartments, whereby a certain shovel effect is attained. This is particularly advantageous when feeding tubes for the material to :be charged are provided and open at, preferably, :a slight distance before the inlet opening, e.g. in a pocket in front of said opening. It is advan- "ice tageous, preferably by proper location of the partition wall, to shape the charging compartments so as to taper toward the rear direction. It will then become capacious near the inlet and can readily receive material. In the same manner the discharging compartment should taper in the forward direction (widen backwardly), whereby the regression of material is prevented to a certain extent. These conditions :are easily obtained by setting the partition Wall at an inclination relative to the plane of rotation of the container. If the inclination is about 45 the sliding surface-s at either side of the wall have the same inclination. It is to be recommended to strive for an inclination substantially corresponding to the angle of repose of the material, where-by the transport is facilitated. If the partition Wall is made to reach to the foremost portion of the discharge opening, the discharge is facilitated and the capaciousness of the charging compartment aimed at the inlet thereof is attained in a simple manner, as is at the same time the restriction of the discharge compartment aimed at. The partition wall is then made to end at some distance from the limitation wall of the container at the inlet side so as to form a passage from the charging compartment to the pocket of the container.

The invention will now be described in connection with its application to a metallurgical treating chamber with a tubular preheater connected thereto and under reference to the accompanying drawings, where:

FIG. 1 is a longitudinal section through those portions of a rotary furnace with tubular heat exchanger which are essential to the illustration of the invention,

FIG. 2 shows an elevator according to the invention in perspective view, and

FIG. 3 shows a fragment of an elevator of the type illustrated in FIG. 2 and intended to be incorporated in a device as shown in FIG. 1.

The device illustrated in FIG. 1 comprises a treating chamber 1 to which a tubular preheater 2 is connected, bot-h enclosed in a furnace shell comprising a plate cover 3 with a refractory lining 4. The furnace device is rotatably supported on roller-s 7 by means of tread rings 6. The furnace is arranged to rotate so that its bottom portion moves toward the spectator of FIG. 1. By the rotation non-treated material is fed through the tubes 10 of the heat exchanger by means of screw conveyors 11 secured therein and to the feeding cone 12 where a screw 13 propels the material into the treating chamber 1. Treating gas is blown into this chamber through the tubes 16 in the heat exchanger and tube 17 terminating in the treating chamber 1 with a nozzle device 18. Treated material is fed to the return chamber 21 from where the material is transported through the tubes 22 by means of conveyor screws 23 secured therein to the lifting device (elevator) 25 according to the invention, which transfers the material up to the top portion of the heat exchanger 2 in which the material is distributed around the tubes transmitting heat thereto.

The lifting device or elevator 25 is illustrated more in detail in FIG. 3. The elevator illustrated consists of a ring shaped element having a cylindrical peripheral or outer limitation wall 31 and an opposite, in this case conically shaped central limitation wall 32 as well as vertical limitation surfaces. At the inlet side these limitation surfaces correspond to a plurality of limitation walls, namely the side wall 34 of the charging compartment 35 and the side wall 36 of the pocket 37 as well as portions of a connection channel between the charging compartment and the pocket which shall be more closely described herein below. At the discharging side the limitation surfaces correspond to theside wall 38 of the pocket and the blocking wall 38 between the pocket and the discharging compartment 40, which in this case can be said to consist of a pocket at the discharging side. Between the charging compartment 35 and the discharging compartment 40 a partition wall 43 extends obliquely relative to the rotational plane of the elevator from the foremost portion 44 of the discharging compartment or opening to a position somewhat apart from the side wall 34 where it terminates with an edge 45. The blocking wall 39 is preferably arranged obliquely relative to the plane of rotation, either in its entirety or with a portion thereof near the partition wall 43. Thereby material that may have entered the discharging compartment 40 from outside at the discharging side when the container travels through the lower portions of its path, is more easily returned to the outside. The charging compartment 35 has a central wall 47 extending to a point 48 some distance up to the edge 45 and further on to a point 49 on the side wall 34. Between the edge 45, the central wall 47 between the points 48 and 49, the peripheral limitation wall31' '(which at this place is removed for the greater part) and the side wall 34 between point 49 and the wall 31 there is formed an opening connecting the charging compartment 35 with the pocket 37. From this opening a channel projects obliquely into said pocket, the channel being formed by the peripheral wall 31, two side Walls extending perpendicularly from wall 31 obliquely to the plane of rotation, viz. a fore wall 51 and a rear wall 52, and a cross wall 53. The side wall 51 can be dispensed with as far as the material transport is concerned but constitutes support for the cross wall 53. The pocket 37 communicates with the discharge compartment 40 through an opening 55 in the blocking wall 39. The pocket 37 is essentially limited by the vertical walls 36 and 38 and a rear wall 57, the cylindrical limiting wall 31 and the central conical limiting wall 32 being limitations in the radial direction. The central limiting Wall 32 extends further into the discharge compartment 40 and forms inner limitations thereto. The inlet opening 58 of the charging compartment 35 is formed between the front edge 59 of the side wall 34, the corner edge between walls 36 and 57 of the pocket 37 and the limitation walls 31 and 32 of the elevator. In the space between the side wall 36 of the pocket and said limitation walls 31 and 32 there is formed an inlet pocket into which feeding members, such. as feeding tubes 22, may open. It is also possible to arrange the inlet opening, wholly or partly, in the vertical limitation surface at the charging side (of the elevator), so that the wall 36 will be situated in the same plane as the wall 34, but the embodiment illustrated is, as a rule, to be preferred. It is also possible to let the feeding tubes 22 open direct through the wall 34 into the charging compartment 35, in which case the entire side limitation surface can be constituted by single annular wall instead of the walls 34 and 36.

The, elevator according to FIG. 3 operates in the following manner. When the inlet opening 58 is in the lower portion of the circular orbit part material is fed through the opening and the peripheral limitation wall 32 then constitutes bottom of the charging compartment 35, which is filled in accordance with the arrows. According as the rotation proceeds in the direction of the arrow the material slides along the wall 32 and the partition wall 43 and through the channel formed by the walls 51, 52, 53 and 31 to the pocket 37, where the material is accumulated at the rear wall 57. During the period when the container holds a substantially upright position with the pocket downwards, the material is substantially stationary therein, but when the container arrives at the upper portion of the circular path the material accumulates on the central limitation wall 32 and when the container is about to take a position with the pocket upwards, the material flows on the wall 32 below the cross wall 53 of the connection channel through the opening 55 to the outlet compartment 40. From here the material is emptied into that chamber that shall receive the material, e.g. the tubular heat exchanger 2. The dis charge does obviously not, at least not wholly take place at the summit position of the outlet opening, but the degree of filling will nevertheless be very high inasmuch as the upper surface of the bulk of the material in the tubular heat exchanger will attain during the rotation a position inclined relative to the horizontal in the descending portion of the cylindrical heat exchanger. The oblique situation of, in particular, the partition wall 43 and the channel wall 52 facilitates the transport, and the inclination of these walls is preferably approximately equal to the angle of repose of the material to be transported. In case the angle of repose is essentially difierent from 45 the partition wall 43 may be replaced by one wall for each of the charging and discharging compartments. The fact that the walls 52 and 53 project a little into the pocket contributes to preventing material to be returned to the charging compartment.

What I claim is:

1. An elevator for lifting fluent solid material from a charging position to a discharging position at a higher level which comprises a container rotatable about a sub stantially horizontal axis in a substantially vertical circular path between said positions; the container having an inlet and an outlet for the material in the fore part thereof, seen in the direction of rotation about said axis; said outlet being arranged substantially at a radial level at least as far from said axis as is said inlet; a partition wall between said inlet and said outlet, said wall forming separate charging and discharging compartments; and a pocket in the rear part of said container communicating with said compartments.

2. The elevator defined in claim 1, characterized in a plurality of the defined containers arranged one after the other.

3. The elevator according to claim 1, characterized in that the charging and discharging compartments are at substantially the same radial level.

4. The elevator defined in claim 1, characterized in that said container is provided with vertical limitation walls, and in that said inlet and outlet openings are positioned in a vertical limitation wall of the container.

5. The elevator defined in claim 1, charaterized in that said partition Wall is so located that the width of the charging compartment decreases and the width of the discharging compartment increases in the backward direction.

6. The elevator defined in claim 5, characterized in that said partition Wall is inclined, relative to the plane of rotation of the container, at substantially the angle of repose of the material.

7. The elevator defined in claim 1, characterized in that said partition wall extends from the fore part of the discharge opening to a position at some distance from said limitation wall of the container at the inlet side so as to form a passage between the charging compartment and said pocket.

8. The elevator defined in claim 7, characterized by the provision of at least one bafiie in said pocket adjacent the passage from the charging compartment, for impeding communication between said pocket and said charging compartment when the container is in the upper portion of its circular path.

9. The elevator defined in claim 8, characterized in that communication between the charging compartment and the pocket is provided at a peripheral limitation wall of the container.

10. The elevator defined in claim 9, characterized in that said communication comprises a channel positioned at an angle substantially equal to the angle of repose of the material, relative to the plane of rotation of the container, and projects into said pocket.

11. The elevator defined in claim 1, characterized by a blocking wall between said pocket and said discharging compartment for obstructing transport of material from said discharging compartment to said pocket.

12. The elevator defined in claim 11, further characterized in that the communication from the pocket to the discharging compartment is arranged at a distance from a peripheral limitation wall of the container.

13. The elevator defined in claim 1, characterized in that said container has a central limitation wall and in that said central limitation wall at least in the discharging compartment tapers from the discharging side towards the charging side.

14. The elevator according to claim 1, characterized in that said charging compartment is provided with a substantially radially extending front limitation wall, and in (that the inlet opening of said charging compartment is positioned in the substantially radially extending front limitation wall of the charging compartment near the vertical outer limitation wall of the compartment.

15. The elevator defined in claim 1, characterized in that feeding tubes for the material to be charged are provided outside said container at the charging side thereof.

16. The elevator defined in claim 15, further characterized in that said feeding tubes open into a pocket arranged in front of said inlet opening.

17. The elevator defined in claim 1, characterized in that feeding tubes for the material to be charged open in the charging compartment.

References Cited by the Examiner UNITED STATES PATENTS 2/1960 Schoonover 263-33 6/1962 Eketorp et al. 26333 

1. AN ELEVATOR FOR LIFTING FLUENT SOLID MATERIAL FROM A CHARGING POSITION TO A DISCHARGING POSITION AT A HIGHER LEVEL WHICH COMPRISES A CONTAINER ROTATABLE ABOUT A SUBSTANTIALLY HORIZONTAL AXIS IN A SUBSTANTIALLY VERTICAL CIRCULAR PATH BETWEEN SAID POSITIONS; THE CONTAINER HAVING AN INLET AND AN OUTLET FOR THE MATERIAL IN THE FORE PART THEREOF, SEEN IN THE DIRECTION OF ROTATION ABOUT SAID AXIS; SAID OUTLET BE- 